In the past, many water treatment methods and apparatuses have been designed and developed. Some are used for the treatment of waste water, to prevent damage to the environment and others are for the purification of raw water, for the safety and health of humans or animals consuming the water. Raw water in this sense means waters from any source, whether raw water, or ground water under the influence of raw water or other water source that requires disinfection and purification before being safe for human consumption. Health and safety concerns relating to potable or drinking water are of an increasing importance in light of deadly pathogens, such as certain strains of E. Coli. Such pathogens are becoming more prevalent due to intensive agricultural techniques and thus more likely to be found contaminating communal raw water sources.
Many of the prior art water treatments involve large and expensive plants, which require the use of metered amounts of chemicals, such as flocculants to remove turbidity and chlorine for disinfection, among others. While suitable for large scale urban facilities, such plants are not economic for smaller population groups, such as remote towns or small groups of people. Further such complex prior art plants require sophisticated monitoring systems and skilled employees to manage the operation of the plant, which expertise can be difficult to find in rural or smaller communities.
What is needed is a simple scalable process and apparatus for the treatment of raw water to render the same fit for human consumption. An attempt was made to design such a plant as shown in my own prior Canadian patent application 2,163,799 filed Nov. 27, 1995. However, the plant I describe therein, while providing reasonable results had some limitations and drawbacks. More particularly, the plant called for the use of a third treatment stage consisting of a deep bed of granulated activated carbon, as a final purification step. This last stage of the process treated the water by adsorption, absorption and biological activity. Unfortunately, such a system results in the activated carbon losing its effectiveness over time, which requires that the activated carbon be replaced periodically. By using larger amounts of activated carbon the effective life of the third stage can be increased, but this simply means it is a bigger job to replace it when required. Since the third stage is a deep bed by design, this is a big, messy, and unpleasant job. As such it is likely to be neglected by unsophisticated or undisciplined operators, resulting in a decline in water quality and safety. Quite simply, the activated carbon will lose its effectiveness over time posing a health risk.
Thus, what is needed is an operator friendly and low maintenance package plant system, which still incorporates the desired treatment requirements without the need for chemicals. Most preferably to maintain such a system operators will not need to shovel out a deep mucky tank of carbon particles as in the prior art.